JP2002140876A - Information recording and reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an information recording and reproducing device, in which the follow-up performance of the repeated control is improved and also the repeated control can be made after one round of even the case when an error signal can not be accurately detected or the periodicity of a signal passing through a low-pass filter is low. SOLUTION: By a delay means 6, the error signal Er passing through the low-pass filter 4 or a driving signal Dr is delayed for the time shorter than the rotating period of a recording medium by the amount of delay time with the low-pass filter 4 and added to the error signal not passing through the low-pass filter 4 or the driving signal to newly settle the error signal driving signal. Also by the delay means 6, a signal delayed by the amount of the rotating period of the recording medium is outputted, and when the error signal can not be accurately detected or the periodicity of the signal passing through the low-pass filter is low, the signal delayed by the amount of rotating period of the recording medium by the delay means is inputted again to the delay means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an optical disk device,
The present invention relates to an information recording / reproducing apparatus for recording or reproducing information on or from a recording medium by a head, such as a magneto-optical disk apparatus or a magnetic disk apparatus, and particularly to an information recording / reproducing apparatus for reducing a displacement of a relative position between a recording medium and a head.

[0002]

2. Description of the Related Art One of the causes of a displacement of a relative position between a recording medium and a head in an information recording / reproducing apparatus is a periodic disturbance caused by rotation of the recording medium.
This includes rotation-synchronous vibration synchronized with rotation, surface vibration, and the like. As a method for improving the performance of following the periodic disturbance, repetitive control is widely known. The repetitive control is a control in which the error signal is delayed by the rotation period of the recording medium, added to the undelayed error signal, and the added signal is output as a new error signal to the stabilizing compensator. This repetition control is described in, for example, “Repetition Control” edited by the Society of Instrument and Control Engineers (Michio Nakano et al.)
Is described in detail.

[0003] By the way, in a system such as an information recording / reproducing apparatus whose control target is truly proper or close to it, it is easy to lose the control stability if the repetitive control for delaying the error signal itself is performed. It is described in. In order to solve this problem, a low-pass filter that removes high-frequency components included in the error signal is provided, and a signal that has passed through the low-pass filter is delayed and added to an error signal that has not passed through the low-pass filter. ,
The book states that stability can be ensured. Further, when a signal that has passed through the low-pass filter is delayed, there is a phase delay (time delay) due to the low-pass filter. Therefore, the delay time is shorter than the rotation period of the recording medium. It is described in the same book that the following performance is higher when the time is shorter by the delay time due to the low-pass filter than when the time is shorter.

When an error signal cannot be detected accurately, such as when a seek operation is performed or when a recording medium has a scratch or a defect, an accurate error signal cannot be input to the delay means. After one round, even if the error signal can be accurately detected at that time, repetitive control cannot be performed only by normal control by the stabilizing compensator. To solve this problem, Japanese Unexamined Patent Application Publication No. 11-8630
When an error signal cannot be detected accurately, such as when performing a track jump or a focus jump, the optical disk control device described in No. 9 delays the signal delayed by the rotation period of the recording medium by the delay unit again. Is input. With this configuration, even when an error signal cannot be accurately detected, control can be repeatedly performed one cycle after the detection.

[0005]

In order to ensure control stability, a low-pass filter is provided, and in order to improve the tracking performance, the delay time is set to be smaller than the rotation period of the recording medium by the delay time of the low-pass filter. If the length (capacity) of the delay means is shorter (smaller) than the rotation period of the recording medium, the signal before one round remains in the delay means. When detection is not possible or when the periodicity of the signal that has passed through the low-pass filter is low, the signal before one round cannot be input to the delay means again, and control cannot be repeated after one round.

Accordingly, an object of the present invention is to set the delay time to a time shorter than the rotation period of the recording medium by the delay time of the low-pass filter so as to improve the tracking performance and accurately detect an error signal. When the periodicity of the signal that has passed through the low-pass filter is low,
It is an object of the present invention to provide an information recording / reproducing apparatus which can be input to a delay means again and can perform control repeatedly after one round.

[0007]

According to the present invention, there is provided a rotating recording medium, a head for storing or reproducing information on or from the recording medium, and an error signal indicating a displacement of a relative position between the recording medium and the head. An information recording / reproducing apparatus comprising: a detecting means for detecting; a driving signal generating means for reducing the error signal; and a driving means for driving the head based on the driving signal. An adding means for adding the error signal and the first signal, a low-pass filter for taking in an output signal of the adding means and removing a high-frequency component therein, and a second signal as an input. A first output terminal for delaying the signal No. 2 by the rotation period of the recording medium and outputting the second signal, and a delay time of the low-pass filter for the second signal which is shorter than the rotation period of the recording medium. A delay means having a second output terminal for outputting the signal with a small time delay, and selecting either the output signal of the low-pass filter or the output signal of the first output terminal to generate the second signal An information recording / reproducing apparatus including a switch input to a delay unit and a unit for supplying an output signal of the second output terminal as the first signal to an addition unit is disclosed.

The present invention further provides a rotating recording medium, a head for recording or reproducing information on or from the recording medium, and a detecting means for detecting an error signal indicating a deviation of a relative position between the recording medium and the head. An information recording / reproducing apparatus comprising: a driving signal generating means for reducing the error signal; and a driving means for driving the head based on the driving signal. Adding means for adding the drive signal and the first signal; a low-pass filter for taking in an output signal of the adding means and removing a high-frequency component therein; and a second signal as an input, A first output terminal for delaying and outputting the second signal by the rotation period of the recording medium; and a time delay of the second signal being smaller than the rotation period of the recording medium by the delay time of the low-pass filter. A delay means having a second output terminal for outputting the output signal from the low-pass filter or the output signal from the first output terminal, and selecting the output signal as the second signal from the delay means. An information recording / reproducing apparatus including a switch for inputting, and a unit for supplying an output signal of the second output terminal as the first signal to an adding unit is disclosed.

Further, according to the present invention, there is provided switching control means for switching a switch, and the switching control means can detect the error signal and, when the periodicity of the output signal of the low-pass filter is high, switch the low-pass filter. When the error signal cannot be detected or when the periodicity of the output signal of the low-pass filter is low so that the output signal of the filter is selectively output, a switch is provided so as to selectively output the output signal from the first output terminal. An information recording / reproducing device for controlling the information is disclosed.

Further, according to the present invention, there is provided switching control means for switching a switch, and the switching control means is provided with the first switch.
Of the output signal V ₁ from the output terminal of the low pass filter and the output signal V ₂ of the low-pass filter, and the absolute value | V ₁ −
When V ₂ | is larger than the allowable value δ, the switch selectively outputs the output signal V _1, and when V ₂ | is smaller than the allowable value δ, the switch selectively outputs the output signal V ₂ ,
A recording / reproducing apparatus that controls a switch is disclosed.

Further, according to the present invention, the output terminal of the signal interpolation means is replaced by a new second output terminal instead of the second output terminal, and the input terminal of the signal interpolation means is connected to the original second output terminal. An information recording / reproducing apparatus is disclosed in which output terminals from delay units before and after a take-out position are connected.

Further, according to the present invention, the delay means is a digital memory having a length (capacity) capable of storing a signal for at least one round of the recording medium, and the delay means is provided at equal intervals or for each rotation angle of the recording medium. An information recording / reproducing apparatus is disclosed, wherein a signal is stored, and the signal is output after being delayed according to time or the rotation angle of the recording medium.

Further, according to the present invention, the generating means is a stabilizing compensator, and the stabilizing compensator has a steady gain means, a phase delay compensator, a phase lead compensator, and a notch filter connected in series. An information storage and playback device is disclosed.

Further, according to the present invention, a switch is provided between the error detecting means and the adding means to determine whether or not to pass an error detection signal. This switch allows the error detection signal to pass when the error signal can be detected. Disclosed is an information recording / reproducing apparatus that receives switching control so as not to pass an error detection signal when an error signal cannot be detected.

Further, the present invention provides a head for recording or reproducing information on or from a recording medium, an error signal detecting means for detecting an error signal indicating a deviation of a relative position between the recording medium and the head, An information recording / reproducing apparatus comprising: a stabilizing compensator for calculating a drive signal for driving the head in a direction to reduce the absolute value; and a driving unit for driving the head by the drive signal. The ratio of the frequency spectrum of the drive signal to the frequency spectrum is larger at frequencies that are integral multiples of the rotation frequency of the recording medium than at the frequencies before and after the frequency, and when the error signal cannot be detected accurately or when the error signal cannot be detected. When the periodicity of the signal is low, the frequency spectrum of the drive signal is a frequency that is an integral multiple of the rotation frequency of the recording medium. In discloses an information recording and reproducing apparatus, characterized in that substantially equal to the frequency spectrum of the driving signal when the high period of the accurately detected can said error signal the error signal.

[0016]

FIG. 1 shows a first embodiment of an information recording (synonymous with storage) reproducing apparatus of the present invention using repetitive control. This information recording / reproducing apparatus includes an error signal detecting means 1, a stabilizing compensator 2, a control object (a head or a rotating shaft for driving the head and its actuator) 3, a low-pass filter (LPF) 4, a switch 5, a delay means 6, It comprises a switch 7, an adding means 8, and switching control means 10 and 11. The error signal detecting means 1 detects a difference between the target value and the head position and outputs an error signal _Er indicating the difference. Here, the target value is a target value when the head follows, such as the position of a track on which information is recorded or reproduced, or the position at which the laser is focused. The stabilization compensator 2 outputs a drive signal _Dr for driving the head based on the signal output from the adder 8. This stabilizing compensator 2 is designed in consideration of servo tracking performance and stability.
For example, as shown in FIG. 4, a steady gain section 21, a phase delay compensator 22, a phase advance compensator 23, a notch filter 24
And so on. Here, the transfer functions of the respective elements 21 to 24 are respectively as follows, for example. Element 21: K element _{22: (s + Z 1)} / (s + P 1) Element _{23: (s + Z 2)} / (s + P 2) Element _{^{24: (s 2 + 2ξ 1}} w n + w 2 n) / (s 2 + 2ξ 2 w n
+ W ² _n )

The control target 3 positions the head based on the drive signal _Dr. The transfer function characteristic of the control target 3 is a characteristic from the drive signal _Dr to the head position, and includes characteristics of a drive unit and a head (not shown).

The low-pass filter 4 removes high-frequency components of the signal output from the adder 8. This is to ensure the stability of the repetitive control. The cut-off frequency of the low-pass filter is set to a frequency at which control stability can be sufficiently ensured. Specifically, when the loop transfer function of the stabilizing compensator and the control target is G (s), the gain of the low-pass filter is (1 + G) at all frequencies.
(S)) is set to be smaller than the gain. For example, it is set to be lower than about 2 kHz. 6 and 7, which will be described later, assume an example of 1 kHz. The low-pass filter 4 outputs all the frequencies in consideration of the fact that the delay means 6 described later outputs a delay output V ₂₁ (or V ₂₂ ) which is delayed by a delay time of the low-pass filter shorter than the rotation period of the recording medium. And a filter (linear phase filter) that delays by the same amount of time. However, when it is difficult to configure a linear phase filter, a filter having a characteristic close to the characteristic, for example, a Butterworth filter is used, and the delay time is the same as the delay time of the linear phase filter closest to the phase characteristic. Interpret that there is.

The switch 5 for the delay means is controlled by the control means 10 so that the control means 10 can accurately detect the error signal, and the low-pass filter 4
When the periodicity of the signal that has passed through is high, the switch 5 is controlled so that the signal V ₁ that has passed through the low-pass filter 4 is used as the input signal V to the delay means 6. Further, the control means 10
When the error signal cannot be detected accurately or when the periodicity of the signal passed through the low-pass filter 4 is low, the signal V ₂ (= V ₂₀ ) delayed by the rotation period of the recording medium by the delay means 6.
To the input signal V to the delay means 6 again. With this configuration, even when an error signal cannot be accurately detected, or when the periodicity of a signal that has passed through the low-pass filter 4 is low, control can be repeatedly performed after one round.

Error signal detected by control means 10 accurately
For example, when you cannot do it,
This is when the recording medium has scratches or defects. Scratches or defects on recording media
Is that, for example, in the case of an optical disc
Defect signal D indicating a fall _fDetecting or monitoring
Can be detected and determined. Low pass
For example, when the periodicity of the signal passing through the filter 4 is low,
For example, when a temporary shock is applied from the outside or when seeking
This is when temporary vibration occurs due to the influence of. Low passfi
The low periodicity of the signal that passed through the filter 4
Its signal V₁The signal V one lap before stored_Two(=
V₂₀The absolute value of the difference from
Can be judged by judging that
You. Here, the threshold value δ is a reference value for determining an allowable value of an error.
And expressed as a ratio (percentage) to the amplitude
Value.

The determination logic of the control means 10 based on the presence or absence of the periodicity is shown below. (1) If | V ₁ −V ₂ | <δ, it is determined that there is periodicity, and the control unit 10 determines that the input signal V to the delay unit 6 is
It controls the switch 5 to select V _1. (2) If | V ₁ −V ₂ | ≧ δ, it is determined that there is no periodicity, and the control unit 10 sets the input unit V to the delay unit 6 as
V ₂ (= V ₂₀ ) is selected. In the control means 10, to also taken into consideration whether a condition can be detected an error signal adopts the following decision logic captures the defect detection signal D _f described above. (1), no defect detection signal D _f (i.e., the error signal detection possible) in and _{| V 1 -V 2 | <δ} ( Yes periodicity)
Then, the switch 5 is controlled so that V = V ₁ . (2), there defect detection signal D _f (i.e., the error signal undetectable), or _{| V 1 -V 2 | ≧ δ} ( no periodicity)
Then, the switch 5 is controlled so that V = V ₂ . In the control unit 10, it is preferable to adding the defect signal D _f, Toka extremely small Toka no occurrence of the defect signal D _f, if Toka ignore the defect signal, and (V ₁ -V ₂₎ δ V ₁ and V ₂ may be selected based on the result of the magnitude comparison with.

The delay unit 6 includes a signal V ₂₀ delayed rotational cycle recording medium, and outputs a signal V ₂₁ was small time delay by a delay time caused by the low pass filter 4 than the rotation period of the recording medium. That is, the rotation period of the recording medium is L ₁ ,
When the delay time of the low-pass filter 4 and L _2, and outputs a signal V ₂₀ that L ₁ delays the (L ₁ -L ₂₎ signal V ₂₁ delayed. The delay unit 6 is composed of a digital memory having a length capable of storing one circumference L ₁ of the signals of at least the recording medium (volume). The details are shown in FIG.

The delay means 6 shown in FIG. 2 is composed of a plurality of delay elements 60, and each delay element stores a signal at equal intervals or for each rotation angle of the recording medium. The total length (capacity) is at least L for one rotation of the recording medium.
_This is the capacity to store ₁ signal. When a new signal is input to the delay means 6 from the right side of FIG. 2, the value in each delay element moves (shifts) one by one in the left direction of the figure.
Is done. The value of the delay element 6a, which is delayed by the rotation period of the recording medium, and the value of the delay element 6b, which is delayed by a delay time of the low-pass filter 4 smaller than the rotation period of the recording medium, are signalized. V _20, V
Output as _{21 to} the outside of the delay means 6.

In the case of storing a signal for each rotation angle of the recording medium at equal intervals, the value of the delay element which is delayed by one round, the delay time of the low-pass filter 4 and the delay time of the recording medium at that time are calculated. The value of the delay element at a point delayed by an angle smaller by the angle corresponding to the product of the angular velocities,
Output to the outside of. When the angular velocity of the recording medium changes, the delay element that outputs a value is changed according to the change in the angular velocity of the recording medium. Instead of moving the value in each delay element, a pointer indicating the address of the delay element to be input / output may be provided and the pointer may be moved. Also, when storing signals at regular intervals,
The signal to be stored may be all the sampled signals, or may be a signal thinned out at regular intervals.
Also, when memorizing the signals thinned out at regular intervals,
In the case of storing a signal for each rotation angle of a recording medium at equal intervals, as shown in FIG. 3, an interpolating means 61 is provided, and when outputting a signal, a plurality of delay elements (for example, 6c) before and after the storage element 6b are output. , using the value of 6d), the signal of the rotational angle of the time is not stored or the recording medium, interpolating linearly or non-linear, the output V _22, put in place of the output V ₂₁ of FIG.

The addition dexterity switch 7, when the can accurately detect the error signal E _r is controlled to input the error signal E _r outputted from the error signal detection unit 1 in the adder 8, the error signal E _r Is not accurately detected, the error signal output from the error signal detecting means 1 is added to the adder 8
Is controlled so as not to input. With this configuration, it is possible to prevent the head from being driven by an erroneous error signal. The switch 7 is turned on by the control means 11.
Receive N / OFF control. That is, when attempting to determine whether it can accurately detect the error signal E _r by the aforementioned defect signal D _f, the determination means 11 takes in the defect signal D _f, if there is a signal D _f (error if the signal undetectable) the switch 7 and OFF, if without signal D _f (error signal detection possible), the switch 7 turned ON. The adder 8 adds the signal from the adder switch 7 and the signal V ₂₁ (or V ₂₂ ) that is delayed by the delay means 6 by a delay time smaller than the rotation period of the recording medium by the delay time of the low-pass filter 4. Output.

The effect of the repetitive control in which the delay time is shorter than the rotation period of the recording medium by the delay time of the low-pass filter will be described with reference to FIGS. FIG. 5 shows the case where repetition control is not used, FIG. 6 shows the case where repetition control using a delay time as the rotation period of the recording medium is used (for example, the example of JP-A-11-86309), and FIG. 7 shows the embodiment of the present invention. This is a result obtained by performing a simulation to obtain a frequency spectrum of an error signal in a case where repetitive control in which a delay time is shorter than a rotation period of a recording medium by a delay time by a low-pass filter is used. Each of the low-pass filters using the repetitive control was a secondary Butterworth filter having a cutoff frequency of 1 kHz. When FIG. 5 in which repetitive control is not used is compared with FIG. 6 in which repetitive control in which the delay time is the rotation period of the recording medium is used, at low frequencies,
Due to the effect of the repetitive control, the error signal shown in FIG. 6 is smaller. However, after the cutoff frequency of the low-pass filter, the use of the repetitive control is affected by the phase delay of the low-pass filter. The error signal is larger. However, in the case of using repetitive control in which the delay time is shorter than the rotation period of the recording medium by the delay time of the low-pass filter, the error signal shown in FIG. It becomes smaller than the indicated error signal. As described above, the information recording / reproducing apparatus of the present invention can improve the tracking performance by setting the delay time of the repetition control to a time shorter than the rotation period of the recording medium by the delay time due to the low-pass filter.

FIGS. 8A and 8B show switching examples of the switches 5 and 7. FIG. FIG. 8A shows the defect signal D _f
Example There turned ON in the middle (with defects) and 8 (b) shows an example defect signal D _f is OFF (no defect).
In FIG. 8A, | V ₁ −V ₂ | <δ is further satisfied.
FIG. 8B shows an example where a case where | V ₁ −V ₂ |> δ occurs on the way. In FIG. 8 (a), in synchronism with the timing at which the defect signal D _f is ON, SW7 is OFF, SW5 becomes V ₂ selected, and FIG. 8 (b) the | V ₁
-V ₂ | in synchronism with the timing at which the> [delta] SW5 becomes V ₂ selected.

FIG. 9 shows a second embodiment of the information recording / reproducing apparatus of the present invention.
It is an embodiment of the present invention. Hereinafter, the information recording / reproducing apparatus shown in FIG. 9 will be described. In the first embodiment, the adder 8
Is an error signal output from the error signal detection means 1, but in the second embodiment, a signal input to the adder 8 is a drive signal output from the stabilization compensator 2. is there. Then, the signal output from the adder 8 becomes a new drive signal and is output to the control target 3. The adder switch 7 is disposed between the stabilizing compensator 2 and the adder 8, and the driving signal output from the stabilizing compensator 2 is added to the adder 8.
Is switched under the control of the control means 21. This control means 21 has the same determination logic as the control means 11 of FIG. The adder switch 7 is placed between the error signal detecting means 1 and the stabilizing compensator 2 so that the error signal output from the error signal detecting means 1 is output to the stabilizing compensator 2.
It is also possible to switch whether or not to input the information. The same effects as in the first embodiment can be obtained by these configurations shown in FIG.

In the repetitive control, the ratio of the frequency spectrum of the drive signal to the frequency spectrum of the error signal is such that at a frequency that is an integral multiple of the rotation frequency of the recording medium,
It is a general property that it is larger than the frequencies before and after that. Then, in the present invention, by performing a time delay smaller than the rotation period of the recording medium by the delay time of the low-pass filter, the tracking performance to an integral multiple of the rotation frequency of the disk is improved, and as a result, the error signal is reduced. In the frequency spectrum of the transfer function up to the drive signal,
The above properties appear. Further, according to the present invention, the same control can be performed at the time of abnormality (when the error signal cannot be accurately detected or when the periodicity of the error signal is low), so that the error signal can be controlled. When the frequency spectrum of the drive signal when it cannot be accurately detected or when the periodicity of the error signal is low, the error signal can be accurately detected at a frequency that is an integral multiple of the rotation frequency of the recording medium, and the periodicity of the error signal is high. It is almost equal to the frequency spectrum of the driving signal at the time. As described above, according to the present invention, the ratio of the frequency spectrum of the drive signal to the frequency spectrum of the error signal is larger at frequencies that are integral multiples of the rotation frequency of the recording medium than at the frequencies before and after it, and
When the error signal cannot be accurately detected or when the periodicity of the error signal is low, the frequency spectrum of the drive signal can be accurately detected at a frequency that is an integral multiple of the rotation frequency of the recording medium. It is almost equal to the frequency spectrum of the drive signal when the periodicity is high.

The defect signal D _f is an example is a signal indicating a defect, which is to be detected occurs by monitoring an example, read data and write data for detecting generated by monitoring the presence or absence of a defect, the recording medium There are various cases, such as an example in which detection is generated by monitoring by software or system. Therefore, the defect signal in the present invention is a broad concept and should be considered to include all types of signals that can determine whether or not an error signal can be accurately detected. However, "accurately" is a matter of the degree of detection, and means the detection of an error signal that enables repetitive control.

[0031]

According to the information recording / reproducing apparatus of the present invention, the follow-up performance can be improved by setting the delay time of the repetition control to be shorter than the rotation period of the recording medium by the delay time of the low-pass filter. . Also, when a correct error signal is not obtained or when the periodicity of the signal passed through the low-pass filter is low, the signal input to the delay means one round before can be input to the delay means again.
After one round, the control can be repeatedly performed, and the tracking performance can be kept high.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of an information recording / reproducing apparatus according to the present invention.

FIG. 2 is a block diagram showing an example of a delay unit of the present invention.

FIG. 3 is a block diagram showing another example of the delay means of the present invention.

FIG. 4 is a block diagram of a stabilizing compensator.

FIG. 5 is a frequency spectrum of an error signal when a conventional information recording / reproducing apparatus that does not use repetition control is used.

FIG. 6 is a frequency spectrum of an error signal when a conventional information recording / reproducing apparatus using repetition control using a delay time as a rotation period of a recording medium is used.

FIG. 7 is a frequency spectrum of an error signal when the information recording / reproducing apparatus of the present invention is used.

FIG. 8 is an example of switching control of switches 5 and 7;

FIG. 9 is a block diagram showing a second embodiment of the information recording / reproducing apparatus of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 error signal detecting means 2 stabilizing compensator 3 controlled object 4 low-pass filter 5 switch for delay means 6 delay means 7 switch for adder 8 adder 10, 11 switching control means

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Manetsu Soma 5-20-1, Kamisumihonmachi, Kodaira-shi, Tokyo F-term in Hitachi Semiconductor Group 5D096 RR06 RR15 RR18 5D118 AA13 BA01 CA05 CB06 CD01 CD09

Claims (9)

[Claims] 1. A rotating recording medium, a head for storing or reproducing information on or from the recording medium, a detecting means for detecting an error signal indicating a deviation of a relative position between the recording medium and the head, An information recording / reproducing apparatus comprising: a driving signal generating unit for reducing a signal; and a driving unit for driving the head based on the driving signal. The error signal provided on the output side of the detecting unit. First
And a low-pass filter which takes in an output signal of the adding means and removes a high-frequency component therein; a second signal as an input, and the second signal is used as a rotation period of the recording medium. A first output terminal for delaying the output by
And a second output terminal for outputting the signal of (c) with a time delay smaller than the rotation period of the recording medium by the delay time of the low-pass filter, and a second output terminal, and an output signal of the low-pass filter or a first output. A switch for selecting one of the output signals from the terminals and inputting the signal as the second signal to the delay means, and supplying the output signal from the second output terminal as the first signal to the addition means Means for recording and reproducing information. 2. A rotating recording medium, a head for recording or reproducing information on or from the recording medium, detecting means for detecting an error signal indicating a deviation of a relative position between the recording medium and the head, An information recording / reproducing apparatus comprising: a driving signal generating means for reducing a signal; and a driving means for driving the head based on the driving signal. The driving signal provided on an output side of the generating means, Adding means for adding the first signal, a low-pass filter for taking in an output signal of the adding means and removing a high-frequency component therein, and a second signal as an input, and applying the second signal to the recording medium. A first output terminal for delaying the output by a rotation cycle and a second output terminal;
And a second output terminal for outputting the signal of (c) with a time delay smaller than the rotation period of the recording medium by the delay time of the low-pass filter, and a second output terminal, and an output signal of the low-pass filter or a first output. A switch for selecting one of the output signals from the terminals and inputting the signal as the second signal to the delay means, and supplying the output signal from the second output terminal as the first signal to the addition means Means for recording and reproducing information. 3. A switching control means for switching the switch, wherein the switching control means can detect the error signal and, when the periodicity of the output signal of the low-pass filter is high, switch the low-pass filter. When the error signal cannot be detected or when the periodicity of the output signal of the low-pass filter is low so as to selectively output the output signal, the switch is controlled so as to selectively output the output signal from the first output terminal. 3. The information recording / reproducing apparatus according to claim 1, wherein 4. provided a switching control means for switching said switch, the switch control means, the output signal V ₂ of the output signal V ₁ and the low-pass filter from said first output terminal
When the absolute value | V ₁ −V ₂ | of the difference is larger than the allowable value δ, the switch selectively outputs the output signal V _1. wherein the switch to selectively output the output signal V _2, according to claim 1 or 2 of the information recording and reproducing apparatus was used to control the switch. 5. An output terminal of the signal interpolation means instead of the second output terminal is a new second output terminal, and an input terminal of the signal interpolation means is provided with a position at which the original second output terminal is taken out. The information recording / reproducing apparatus according to claim 1 or 2, wherein output terminals from delay units before and after (a) are connected. 6. The delay means is a digital memory having a length (capacity) capable of storing a signal for at least one round of the recording medium, and outputs the signal at equal intervals or for each rotation angle of the recording medium. 3. The information recording / reproducing apparatus according to claim 1, wherein the information is recorded and output after delaying a signal according to time or a rotation angle of the recording medium. 7. The stabilizing compensator as the generating means, wherein the stabilizing compensator includes a steady gain means, a phase lag compensator, a phase lead compensator, and a notch filter connected in series. 1 or 2 information storage and playback device. 8. A switch is provided between the error detecting means and the adding means to determine whether or not to pass an error detection signal. The switch allows the error detection signal to pass when an error signal can be detected. The information recording / reproducing apparatus according to any one of claims 1 to 7, wherein when information cannot be detected, switching control is performed so as not to pass an error detection signal. 9. A head for recording or reproducing information on or from a recording medium, an error signal detecting means for detecting an error signal indicating a deviation of a relative position between the recording medium and the head, and an absolute value of the error signal. An information recording / reproducing apparatus comprising a stabilizing compensator for calculating a drive signal for driving the head in a direction in which the error signal is reduced, and a driving unit for driving the head with the drive signal, wherein a frequency spectrum of the error signal is The ratio of the frequency spectrum of the drive signal is larger than the frequency before and after the frequency that is an integral multiple of the rotation frequency of the recording medium, and when the error signal cannot be detected accurately or when the period of the error signal The frequency spectrum of the drive signal when the property is low, the frequency is an integer multiple of the rotation frequency of the recording medium, Information recording and reproduction apparatus according to the frequency spectrum of the driving signal when the error signal is high periodicity of the accurately detected can said error signal, characterized in that approximately equal.